Underside lockup device for quarter-size plate



3,452,674 UNDERSIDE LOCKUP DEVICE FOR QUARTER-SIZE PLATE Filed Aug. 7, 1967 c. H. PORTER July 1, 1969 Sheet 5 3 H E 2A. 12 n '[H U D DD DU mm. mm mm. M 4 M. m. MW. mm .UUDU HUB HU m m mm mm UH UB7 U n Una M n w P 2 m Iv m INVENTOR. CLIVE H. PORTER FIG. I.

July I, 1969 c. H. PORTER 3,452,674 I UNDERSIDE LOCKUP DEVICE FOR QUARTER-SIZE PLATE Filed Aug. 7, 1967 Sheet 2 of 2 INVENTOR. CLIVE H. PORTER PIC-3.9.

United States Patent US. Cl. 101-378 3 Claims ABSTRACT OF THE DISCLOSURE A printing plate locking device for attaching stereotype printing plates to plate cylinders of rotary printing machines, adapted to fastening either half-shell or quarter-shell size plates on the plate cylinders by clamps which engage corresponding grooves on the underside of the plates.

This invention relates to underside locking devices for printing plates in general and to devices of this kind for half-shell and quarter-shell plates in particular.

Background of the invention This invention relates to clamping devices on plate cylinders of rotary printing machines, particularly for newspaper printing machines, for the stereo-type printing plates. These printing plates usually contain one page of the newspaper, the so-called broadsheet, but in some instances it is desirable to print two pages of half the size of the broad-sheet instead of the same, the so-called tabloid size. The invention is directed to new and improved clamping devices foreither the plates for the full page or for the half page (tabloid page), which may be operated without replacing or exchanging mechanisms.

The prior practice only had underside clamping devices, called otherwise tension locking devices, for either semi-cylindrical plates, as in newspaper printing machines, or for quarter-cylindrical plates, such as they are used in the magazine printing machines. There is a problem in newspaper production when the publisher wants to have both kinds of papers, i.e., full page and tabloid page sheets. conventionally the printing plates carry two tabloid pages, but when it occurs during the daily production that something on one of these pages has to be changed, in that case the entire plate will have to be replaced with a new one. This invention solves this problem in a Very convenient and simple manner.

Summary The invention consists in such novel features, construction arrangements, combinations of parts and improve ments as may be shown and described in connection with the device herein disclosed by way of example only and as illustrative of a preferred embodiment. Objects and advantages of the invention will be set forth in part hereafter or in part will be obvious herefrom or may be learned 'by practicing the invention, the same being realized and attained by means of the instrumentalities and combinations pointed out in the appended claims.

It is an object of this invention to provide contrivances for clamping either semi-cylindrical or quarter cylindrical printing plates on plate cylinders of rotary printnig machines by underside locking means.

Furthermore, it is an object of the invention to provide underside printing plate locking means which are arranged to be pivotally swung downwardly below the surface of the plate cylinder.

Another object of the invention is to provide underside plate locking means which are movable in pairs in 3,452,674 Patented July 1, 1969 unison from an operable to an inoperable position in the plate cylinder.

Yet another object of the invention is to provide for intermediate underside locking means which are operated in their operable position by the main plate locking means on the plate cylinder.

A further object of the invention is to provide for intermediate locking devices for locking quarter cylindrical printing plates which can be easily and conventionally operated from an operative to an inoperative position without the use of tools.

Various further and more specific purposes, features and advantages will clearly appear from the detailed description given below taken in connection with the accompanying drawings which form part of the specification and illustrates merely by way of example one embodiment of the device of the invention. In the following description and in the claims, parts will be identified by specific names for convenience but such names are intended to be as generic in their application to similar parts as the art will permit. Like reference char acters denote like parts in the several figures of the drawings.

Brief description of the drawings In the drawings:

FIG. 1 a side view of a plate cylinder with undersible plate locking devices,

FIG. 2 a cross-section of the plate cylinder along the line 2-2 in FIG. 1, showing the plate locking devices,

FIG. 3 another cross-section of the plate cylinder shown in FIG. 1, taken along the line 2-2 thereof, showing another embodiment of the intermediate locking device shown in FIG. 2, partly broken away,

FIG. 4 a cross-section of the intermediate underside locking device in a larger scale, shown in the operative position, partly broken away,

FIG. 5 the underside locking device as shown in FIG. 4. shown in the inoperative position,

FIG. 6 a side view of the locking device shown in FIG. 4, and FIG. 5, partly broken away,

FIG. 7 a cross-section of another embodiment of the intermediate underside locking device shown in FIG. 4, partly broken away,

FIG. 8 a cross-section of the embodiment of the device shown in FIG. 7, partly broken away,

FIG. 9 a side view of the locking device shown in FIG. 7 and FIG;- 8, partly broken away taken along the line 99 in FIG. 7.

Description of the preferred embodiment Referring now in more detail to the drawings illustrating a preferred embodiment by which the invention may be realized, there is in FIG. 1 a newspaper rotary printing machine plate cylinder 11 in which the conventional underside lockup units 12 are located in the manner as it is disclosed in the Patent No. 2,832,288. Additional intermediate plate clamping units 13 are placed in plate cylinder 11 at angles from units 12. It becomes evident from FIG. 2 and FIG. 3 that either semi-cylindrical stereo-type printing plates 14 or quarter-cylindrical plates 15 can be clamped on cylinder 11. The intermediate clamping units 13 are shown in more detail in FIGS.

49. Each unit comprises two pairs of plate clamps 16.

The clamps have hook-like ends 17 which are shaped in such a manner as to engage corresponding grooves 18 in the stereo-type printing plates 15. Clamps 16 are pivotally mounted on shafts 19. Shafts 19 are located in units 13 in parallel alignment with one another and with the axis of cylinder 11. Each of clamps 16 has a rear extension 20 which is diametrically opposed to hook end 17. Extension 20 is furcated and carries a short shaft 21. A

linking bar 22 connects the extension 20 so that clamps 16 can be rotated in unison in a parallelogram-like manner on shafts 19. A torsion spring 23 is arranged on one of short shafts 21 of each pair of clamps 16. One end of spring 23 is attached to the center of one end of one short shaft 21 while the other end of spring 23 is located in the body 24 of unit 13 (FIG. 6). Spring 23 is arranged in such a manner that it will swing around toggle-like with the rotary motion of the pair of clamps 16, and thus is apt to hold the clamps in both the operative and the inoperative position (FIG. 4 and FIG. 5 respectively). Units 13 are slidably arranged in grooves 25 in plate cylinder 11 and are held in the desired axial relationship to one another by dovetailed blocks 26 in corresponding grooves 27 by screws 28. Torsion toggle-like acting springs 23 can b substituted with helical tension springs 29 as shown in FIG. 7 and. 8. A spring-loaded detent 30 is placed in body 24 on one side of each extension 20 of clamps 16 for holding the pair of clamps 16 in the inoperative position, when tension springs are used instead of the torsion springs as shown in FIG. 9.

Operation In a conventional production process, semi-cylindrical plates 14 are clamped on the plate cylinders of the newspaper production machines by underside locking devices such as shown in FIG. 2 and FIG. 3. Each one of these platescontains the composition of one newspaper page. However, there are occasions when it is desirable to produe papers of half the page size of the newspaper. In such cases, the printing plate either would have to carry the compositions of two pages, or the plates themselves would have to be half the size of the newspaper page plate. This means that such a plate would be quartercylindrical (15 in FIG. 2 and FIG. 3). In the latter case, the clamps 16 are merely swung upwardly into operative position, which can be done very simply by hand without the necessity of using a tool, where they remain in upright position due to the toggle action of the spring (23, or 29). Quarter-cylindrical plates now can be safely tightened in pairs by the conventional underside locking device because the intermediate clamping device is apt to transmit the tensioning forces from one plate to the other. It is obvious that the clamps 16 can be easily swung down so that the hook-like ends 17 lay below the surface of the plate cylinder, enabling the printer to use the regular semi-cylindrical printing plate. The centrifugal forces acting on rear extensions 20 obviously add to the spring forces.

I claim:

1. An improved printing plate cylinder for a printing press, said cylinder having underside locking devices for securing semi-cylindrical stereotype printing plates thereto, and additional underside locking devices for securing quarter-cylinderical stereotype printing plates to said cylinder wherein said additional locking devices comprises removable units for location substantially halfway intermediate said locking devices for the semi-cylindrical printing plates, a pair of shafts mounted within each of said units parallel to each other and to the longitudinal axis of said cylinder, a clamping member pivotally mounted on each of said shafts, each said member having a hook-like end which extends above the surface of said cylinder when said members are in an exact position so as to engage an undercut groove on a quarter-cylindrical plate for clamping it to said cylinder, a linkage bar connected to said members at the end opposite said hooklike end for causing said members to move in unison when being pivoted about said shafts, biasing means for urging said members to remain in the erect position, and means for locking said members in the inoperative position, whereby said members may be maintained in an erect and operative position for securing quarter-cylindrical plates onto said printing cylinder and are so mounted for movement in unison to a non-erect and inoperative position so as not to interfere with the securement of semi-cylindrical plates on said cylinder.

2. The improved printing cylinder according to claim 1 wherein said biasing means and said locking means comprises a torsion spring attached at one end thereof to one of said clamping members at its end opposite said hook-like end and attached at the other end thereof to the body of said unit, whereby said spring is caused to snap from a first position to a second position as said members are pivoted about said shafts so that when said spring is in the first position it will bias said members in the erect and operative position, and when said members are moved to the nonerect and inoperative position said spring will snap to said second position for biasing said members in said nonerect and inoperative position.

3. The improved printing cylinder according to claim 1 wherein said biasing means comprises a tension spring attached at one end thereof to one of said clamping members at its end opposite said hook-like end and attached at the other end thereof to the body of said unit, and wherein said locking means comprises a detent member located in the body of said unit so as to engage said linkage bar when said clamping members are moved to the nonerect and inoperative position for holding said members in the nonerect and inoperative position.

References Cited UNITED STATES PATENTS 2,679,800 6/1954 Crafts l0l--378 2,709,406 5/1955 Knowles 101-378 2,732,798 1/1956 Chase l01-4l5.1 XR 2,915,010 12/1959 Crafts 101378 3,123,196 3/1964 Paone et al. 197-186 ROBERT E. PULFREY, Primary Examiner.

C. D. CROWDER, Assistant Examiner. 

